In the field of printing, the most common type has been the printer which impacts against record media that is caused to be moved past a print line or line of printing. As is well-known, the impact printing operation depends upon the movement of impact members, such as print hammers or wires or the like, which are typically moved by means of an electromechanical system and which may, in certain applications, enable a more precise control of the impact members.
In the field of dot matrix printers, it has been quite common to provide a print head which has included therein a plurality of print wire actuators or solenoids arranged or grouped in a manner to drive the respective print wires a precise distance from a rest or non-printing position to an impact or printing position. The print wires are generally either secured to or engaged by the solenoid plunger or armature which is caused to be moved such precise distance when the solenoid coil is energized and wherein the plunger normally operates against the action of a return spring.
It has also been quite common to provide an arrangement for grouping of such solenoids in a circular configuration to take advantage of reduced space available in the manner of locating the print wires in that area fron the solenoid to the front tip of the print head adjacent the record media. In this respect, the actuating ends of the print wires are spaced in accordance with the circular arrangement and the operating or working ends of the print wires are closely spaced in vertically-aligned manner adjacent the record media. The availability of narrow or compact actuators permits a narrower print head to be used and thereby reduces the width of the printer because of the reduced clearance at the ends of the print line. The print head can also be made shorter because the narrow actuators can be placed in side-by-side manner closer to the record media for a given amount of wire curvature.
In the wire matrix printer, the print head structure may be a multiple-element type with the wire elements aligned in a vertical line and supported on a print head carriage which is caused to be moved or driven in a horizontal direction for printing in line manner, while the drive elements or transducers may be positioned in a circular configuration with the respective wires leading to the front tip of the print head.
Alternatively, the printer structure may include a plurality of equally-spaced, horizontally-aligned, single-element print heads which are caused to be moved in back-and-forth manner to print successive lines of dots in making up the lines of characters. In this latter arrangement, the drive elements or transducers are individually supported along a line of printing. These single wire actuators or solenoids are generally tubular or cylindrically shaped and include a shell which encloses a coil, an armature, and a resilient member arranged in manner and form wherein the actuator is operable to cause the print wire to be axially moved a small precise distance in dot matrix printing.
In the concept of dot matrix printing, it is generally desired to place the print element actuators in a position to allow characters to be printed in serial manner and this placement requires that the print wire or like print element actuators be very closely spaced with respect to each other. Since the print actuators are generally much larger in the size than the diameter of the printed dot, a relatively long wire or like element must be provided to bring the desired print activity from its source, such as a moving armature or plunger or the like, to a vertical closely-spaced column arranged in a pattern such that a column of closely-spaced, tangentially coincident dots will be produced on the record media if all actuators are fired or actuated at one time.
Representative documentation in the design of a dot matrix print head includes U.S. Pat. No. 2,338,865, issued to L. L. Matson on Jan. 11, 1944, which discloses a body having a pair of spaced holes through an end portion and a lead wire extends through one hole, across the end portion and through the other hole, after which the lead wire end may be cemented in place.
U.S. Pat. No. 3,184,532, issued to F. T. Spera on May 18, 1965, discloses a device adapted for attachment to a printed circuit panel having elements on an insulating board and including an aperture and a notch or recess for receiving a lead wire of the device. Each cylindrical element has grooves for the lead wires which are bent and soldered in place.
U.S. Pat. No. 3,486,224, issued to W. O. Chaney on Dec. 30, 1969, discloses a method of securing a coil form to a printed circuit board by inserting coil form mounting feet through holes in the board and passing coil ends through other holes associated with circuit elements on the board and then soldering the coil ends.
U.S. Pat. No. 3,536,869, issued to F. H. Renshaw on Oct. 27, 1970, discloses a switch device for use with printed circuit boards and having a plug with slots along the side for mounting contact blades.
And, U.S. Pat. No. 3,991,347, issued to R. D. Hollyday on Nov. 9, 1976, U.S. Pat. No. 4,103,267, issued to W. W. Olschewski on July 25, 1978, and U.S. Pat. No. 4,249,229, issued to T. E. Hester on Feb. 3, 1981, disclose various means for securing electrical devices to circuit board or like substrate members.